The present invention relates to a novel and stable hydrogen peroxide adduct and a process for preparing same. Particularly, the present invention is concerned with a crystallized, stable histidine-hydrogen peroxide adduct and a process for preparing same.
One method for crystallizing hydrogen peroxide which is liquid is to make hydrogen peroxide into an adduct. Adducts of hydrogen peroxide are broadly classified into the following two according to liquid properties of aqueous solutions thereof. The two are those whose aqueous solutions exhibit alkalinity such as sodium percarbonate and sodium perborate and those whose aqueous solutions exhibit acidity such as urea peroxide.
Sodium percarbonate and sodium perborate are used widely as oxygen type bleaches, pipe detergents, etc.
Urea peroxide is used as a decoloring agent for the treatment of hair before hair dyeing or as an oxidizing agent for dyes.
They are each prepared by contacting an aqueous solution of sodium carbonate, sodium metaborate, or urea, with hydrogen peroxide to crystallize sodium percarbonate, sodium perborate or urea peroxide.
However, these conventional hydrogen peroxide adducts involve the following problems.
(1) Since aqueous solution of sodium parcarbonate and sodium perborate are alkaline, hydrogen peroxide is apt to decompose and so they are unstable.
(2) Aqueous solutions of sodium percarbonate and sodium perborate erode proteinaceous materials such as silk and wool because of their strong alkalinity, so they are not only unsuitable for the bleaching of those materials but also involve the danger of injuring the human body.
(3) As to urea peroxide, an aqueous solution thereof exhibits acidity.
(4) It is difficult to preserve sodium percarbonate, sodium perborate and urea peroxide over a long period under high temperature and high humidity conditions because they are easily decomposed by the moisture contained in air.
(5) Since urea peroxide is easily decomposed rapidly by shock or heat, it is necessary to handle it carefully.
It is the object of the present invention to provide a novel hydrogen peroxide adduct free of the above-mentioned problems.